On 6/26/2018 4:55 PM, Toke Høiland-Jørgensen wrote:
Manikanta Pubbisetty <mpubbise@xxxxxxxxxxxxxx> writes:
We can still invoke netif stop/wake APIs when wake_tx_queue is
implemented but this could lead to packet drops in network layer;
adding stop/start logic for software TXQs in mac80211 instead makes
more sense; the change proposed adds the same in mac80211.
I agree with the approach; having packets queued in mac80211 while the
queues are stopped also means that CoDel can react to them when they are
resumed again.
Agreed!!
+ list_for_each_entry_rcu(sta, &local->sta_list, list) {
+ if (!atomic_read(&sta->txqs_paused))
+ continue;
+
+ atomic_set(&sta->txqs_paused, 0);
I'm not terribly well-versed in the kernel atomics, but doesn't the
split of read and set kinda defeat the point of using them? Also, as
this is under RCU, why do you need an atomic in the first place?
Valid point, txqs_paused is set in ieee80211_tx_dequeue; I was thinking
a case where tx_dequeue is called without rcu_read_lock but seems that
is not the case. All drivers using wake_tx_queue seems are using
rcu_read_lock before tx_dequeue; can there be a case where tx_dequeue is
called without rcu_read_lock?
Manikanta
